A permanent magnet synchronous motor is a high-power and high-efficiency motor and it is widely used in the industry for hybrid electric vehicles and the like. The motor's high power and high efficiency at least in part rely on the fact that the permanent magnet synchronous motor has no winding in the rotor thereof and a concentric winding in the stator thereof.
However, there is a significant disadvantage associated with the use of concentric windings. In particular, the concentrated winding causes harmonic current components in a back electromagnetic motive force voltage. For instance, a fifth harmonic current component and/or a seventh harmonic current component, etc., are often found in the back electromagnetic motive force voltage, in addition to a fundamental wave component. These harmonic current components in the back electromagnetic motive force voltage disturb the current control of the permanent magnet synchronous motor by generating a harmonic current that distorts the motor's current waveform. The harmonic current also causes a torque ripple in the motor as well as heat loss from the stator of the motor, thereby reducing the motor's overall efficiency. Although some algorithms have been proposed for suppressing the harmonic current, the complicated calculations required by those algorithms often render them less desirable.